P0306 on 96 Windstar 3.8??

[martymoose32]

Hello all, and Merry Christmas.

I had my van checked at Autozone and they gave me a P0306 code. Now, I searched this board and I did not see anything specific for the 96. The only problem I have is a rough idle. Once you accelerate, it is fine.

I have changed the IAC.

The motor has been changed 20,000 miles ago. I had the idle problem before the engine went, and I still have it. I had the engine checked after the install and they said no vacuum leaks.

Any ideas where to start??

Thanks.

[wiswind]

P0306 is cylinder #6...which is the front, driver side of the engine.
EGR ports being clogged normally causes a misfire on Cylinders 1 and / or 4.....as they are the farthest away from the EGR valve.....and the last to clog......so the misfire comes from the last 1 or 2 cylinders getting all the EGR flow.

You could try moving the spark plug from that cylinder to another cylinder. A look at the plug from cylinder #6....compared to Cylinder #5 might be an idea.

Another possibility is a bad spark plug wire.

The coil pack fires 2 cylinders at a time......
It is possible that there is a problem with it....but not as likely. Thing is.......to do any kind of a visual inspection (they can develop cracks in the epoxy body...and that is where they arc)...you have to remove it from the car. When I decided to remove mine to inspect it..........I just bought a new one and installed it.

The other (more likely prospect) is an issue with the fuel injector for cylinder #6.
Unfortunately....removing the fuel injector(s) requires removing the upper intake manifold.
You may be lucky....and only need a physical cleaning of the spray end of the injector.
I had to remove mine....and spray cleaner onto the end of the injector to remove the crud.

Or....there could be an electrical issue with it.....
The fuel injectors have 1 terminal that is "hot" at all times that the ignition is on......the PCM provides a momentary path to ground to the other terminal....to activate the injector. A check of the wiring....including at the electrical connector to the injector might be something to try. If the injector is not spraying gasoline....one would think that the spark plug for that cylinder would be significantly cleaner than the plugs from the other cylinders.
That is in keeping with a misfire that I had on cylinder #2.....the plug was much cleaner than the other cylinders.

[martymoose32]

Thanks wiswind, I will look into all suggested and reply as soon as possible. (raining today)

[martymoose32]

I checked the #6 plug and wire. Everything looked normal. I did however notice something else. The linkage was disconnected for the IMRC on bank 1. It looks like the grommet was no longer there. I fashioned one from a plastic wall anchor cut about 1/4". fit like a glove. Works great, too! The linkage for bank 2 was still connected. It made my idle a little better-I no longer have the miss 'till 2000 rpm, then a burst in speed. I also found corrosion around positive terminal on battery. Disconnected cable and cleaned (reset code). Light came back a few drive cycles later. Now, I need to go back to Autozone. Will do after holidays.